export function addClass(el: Element, className: string) {
  if (!el.classList.contains(className)) {
    el.classList.add(className)
  }
}

export function removeClass(el: Element, className: string) {
  el.classList.remove(className)
}

export function getMaxZIndex (): number {
  return Array.from(document.all).reduce((r, e) => Math.max(r, +window.getComputedStyle(e).zIndex || 0), 0)
}
